Steerable microwave backhaul transceiver

ABSTRACT

A first microwave backhaul transceiver may comprise a reflector and a signal processing subassembly. The signal processing subassembly may comprise a plurality of antenna elements positioned at a focal plane of the reflector. The signal processing subassembly may process a plurality of microwave signals corresponding to the plurality of antenna elements using a corresponding plurality of phase coefficients and a corresponding plurality of amplitude coefficients. The signal processing subassembly may adjust a radiation pattern of the plurality of antenna elements during operation of the signal processing subassembly through adjustment of the phase coefficients and/or the amplitude coefficients.

PRIORITY CLAIM

This application claims priority to and the benefit of the followingapplication(s), each of which is hereby incorporated herein byreference:

U.S. provisional patent application 61/809,935 titled “MicrowaveBackhaul” filed on Apr. 9, 2013;

U.S. provisional patent application 61/881,016 titled “MicrowaveBackhaul Methods and Systems” filed on Sep. 23, 2013; and

U.S. provisional patent application 61/884,765 titled “MicrowaveBackhaul Methods and Systems” filed on Sep. 23, 2013.

BACKGROUND

Limitations and disadvantages of conventional approaches to microwavebackhaul will become apparent to one of skill in the art, throughcomparison of such approaches with some aspects of the present methodand system set forth in the remainder of this disclosure with referenceto the drawings.

BRIEF SUMMARY

Methods and systems are provided for a steerable microwave backhaultransceiver, substantially as illustrated by and/or described inconnection with at least one of the figures, as set forth morecompletely in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example microwave backhaul link between a firstmicrowave backhaul transceiver and a second microwave backhaultransceiver.

FIG. 2 shows an example implementation of a steerable microwave backhaultransceiver.

FIG. 3 shows an example implementation of the subassembly of FIG. 2.

FIG. 4A shows a first example implementation of the circuitry of FIG. 3.

FIG. 4B shows a second example implementation of the circuitry of FIG.3.

FIGS. 5A-5C show example configurations of the beamforming circuitry ofFIG. 4A.

FIGS. 6A-6C show example configurations of beamforming components of thedigital signal processing circuitry of FIG. 4B.

FIG. 7A shows adjustment of an azimuth angle of a lobe of a radiationpattern of a microwave backhaul assembly.

FIG. 7B shows adjustment of an elevation angle of a lobe of a radiationpattern of a microwave backhaul assembly.

FIG. 8 shows a microwave backhaul assembly configured for two concurrentbackhaul links in two different directions.

DETAILED DESCRIPTION

As utilized herein the terms “circuits” and “circuitry” refer tophysical electronic components (i.e. hardware) and any software and/orfirmware (“code”) which may configure the hardware, be executed by thehardware, and or otherwise be associated with the hardware. As usedherein, for example, a particular processor and memory may comprise afirst “circuit” when executing a first one or more lines of code and maycomprise a second “circuit” when executing a second one or more lines ofcode. As utilized herein, “and/or” means any one or more of the items inthe list joined by “and/or”. As an example, “x and/or y” means anyelement of the three-element set {(x), (y), (x, y)}. As another example,“x, y, and/or z” means any element of the seven-element set {(x), (y),(z), (x, y), (x, z), (y, z), (x, y, z)}. As utilized herein, the terms“e.g.,” and “for example” set off lists of one or more non-limitingexamples, instances, or illustrations. As utilized herein, circuitry is“operable” to perform a function whenever the circuitry comprises thenecessary hardware and code (if any is necessary) to perform thefunction, regardless of whether performance of the function is disabled,or not enabled, by some user-configurable setting. As used herein,“microwave” frequencies range from approximately 300 MHz to 300 GHz and“millimeter wave” frequencies range from approximately 30 GHz to 300GHz. Thus, the “microwave” band includes the “millimeter wave” band.

FIG. 1 depicts an example microwave backhaul link between a firstmicrowave backhaul transceiver and a second microwave backhaultransceiver. Shown are a tower 108 to which access network antennas 112and remote radio head (RRH) 110 are attached, a baseband unit 104, atower 122 a to which microwave backhaul transceiver 120 a (comprisingsubassembly 114 a and reflector 116 a) is attached, and a tower 122 b towhich microwave backhaul transceiver 120 b (comprising subassembly 114 band reflector 116 b) is attached. At any particular time, there may beone or more active (i.e., carrying traffic or synchronized and ready tocarry traffic after a link setup time that is below a determinedthreshold) links 106 (shown as wireless, but may be wired or optical)between the RRH 110 and the BBU 104. At any particular time, there maybe one or more active backhaul links 118 between the pair of backhaultransceivers 120 a and 120 b and/or between one of the transceivers 120a and another one or more backhaul transceivers not shown.

The antennas 112 are configured for radiating and capturing signals ofan access network (e.g., 3G, 4G LTE, etc. signals to/from mobilehandsets). Although the example pair of microwave transceivers 120 a and120 b are used for backhauling cellular traffic, this is just oneexample type of traffic which may be backhauled by microwavetransceivers, such as 120 a and 120 b, that implement aspects of thisdisclosure.

For an uplink from a mobile handset to the core network 102, theantennas 112 receive signals from the handset and convey them to the RRH110. The RRH 110 processes (e.g., amplifies, downconverts, digitizes,filters, and/or the like) the signals received from the antennas 112 andtransmits the resulting signals (e.g., downconverted I/Q signals) to thebaseband unit (BBU) 104 via link(s) 106. The BBU 104 processes, asnecessary, (e.g., demodulates, packetizes, modulates, and/or the like)the signals received via link(s) 106 for conveyance to the microwavebackhaul transceiver 120 a via link 113 a (shown as wired or optical,but may be wireless). The microwave backhaul transceiver 120 aprocesses, as necessary (e.g., upconverts, filters, beamforms, and/orthe like), the signals from BBU 104 for transmission via the subassembly114 a and reflector 116 a over microwave backhaul link(s) 118. Themicrowave transceiver 120 b receives the microwave signals overmicrowave backhaul link(s) 118 via the subassembly 114 b and reflector116 b, processes the signals as necessary (e.g., downconverts, filters,beamforms, and/or the like) for conveyance to the cellular serviceprovider core network 102 via link 113 b.

For a downlink from the core network 102 to the mobile handset, datafrom the core network 102 is conveyed to microwave backhaul transceiver120 b via link 113 b. The transceiver 120 b processes, as necessary(e.g., upconverts, filters, beamforms, and/or the like), the signalsfrom the core network 102 for transmission via the subassembly 114 b andreflector 116 b over link(s) 118. Microwave transceiver 120 a receivesthe microwave signals over the microwave backhaul link(s) 118 via thesubassembly 114 a and reflector 116 a, and processes the signals asnecessary (e.g., downconverts, filters, beamforms, and/or the like) forconveyance to the BBU 104 via link 113 a. The BBU 104 processes thesignal from transceiver 120 a as necessary (e.g., demodulates,packetizes, modulates, and/or the like) for conveyance to RRH 110 vialink(s) 106. The RRH 110 processes, as necessary (e.g., upconverts,filters, amplifies, and/or the like), signals received via link 106 fortransmission via an antenna 112.

FIG. 2 shows an example implementation of a steerable microwave backhaultransceiver. The depicted transceiver 120 represents each of thetransceivers 120 a and 120 b described above with reference to FIG. 1.The example transceiver 120 comprises the subassembly 114 mounted to asupport structure 204 (which may, in turn, mount the assembly to themast/tower 122, building, or other structure, not shown in FIG. 2), anda link 113 which represents each of the links 113 a and 113 b. Thesubassembly 202 comprises an antenna array 202 which in turn comprises aplurality of antenna elements. The subassembly 202 may be mounted suchthat the antenna elements are positioned at or near a focal plane of thereflector 116. The subassembly may comprise, for example, one or moresemiconductor dies (“chips”) arranged on one or more printed circuitboards. The antenna elements may be, for example, horns and/ormicrostrip patches. In the example implementation depicted, the antennaelements capture signals reflected by reflector 116 for reception andbounce signals off the reflector 116 for transmission. In anotherimplementation, the antenna elements may directly receive backhaulsignals, or receive them through a lens, for example. The radiationpattern 208 of the antenna array 202 corresponds to a radiation pattern206 after reflection off the reflector 116 (Although the radiationpatterns may comprise multiple lobes, only a main lobe is shown forsimplicity of illustration).

FIG. 3 shows an example implementation of the subassembly of FIG. 2. Theexample subassembly 114 comprises four feed horns 306 ₁-306 ₄, andcircuitry (e.g., a chip or chipset) 302. The circuitry 302 drivessignals to the horns 306 ₁-306 ₄ via one or more of feed lines 304 ₁-304₈ for transmission and receives signals from the horns 306 ₁-306 ₄ viafeed lines 304 ₁-304 ₈ for reception. The circuitry 302 is operable tocontrol the phases and/or amplitudes of signals output to the feed lines304 ₁-304 ₈ so as to achieve desired transmit radiation patterns.Similarly, the circuitry 302 is operable to control the phases and/oramplitudes of signals received from the feed lines 304 ₁-304 ₈ so as toachieve desired receive radiation patterns.

The feed lines 304 ₁-304 ₄ correspond to a first polarization and thefeed lines 304 ₅-304 ₈ correspond to a second polarization. Accordingly,the subassembly 114 may be operable to concurrently receive twodifferent signals on the same frequency but having differentpolarizations, concurrently transmit two different signals on the samefrequency but having different polarizations, and/or concurrentlytransmit a first signal having a first polarization and receive a secondsignal having a second polarization. Furthermore, the radiation patternfor the two polarizations may be controlled independently of oneanother. That is two independent sets of amplitude and phase beamformingcoefficients may be maintained by circuitry 302, with the first set usedfor feed lines 304 ₁-304 ₄ and the second set used for feed lines 304₅-304 ₈.

FIG. 4A shows a first example implementation of the circuitry of FIG. 3.In the example implementation shown, the circuitry 302 comprises analogfront-ends 402 ₁-402 ₈, a beamforming circuit 404, analog-to-digitalconverter (ADC) 406, one or more sensors 414, digital circuitry 408, anda digital to analog converter (DAC) 440. The circuitry 302 outputsreceived data onto the link 113 (e.g., coaxial cable) and receivesto-be-transmitted data via link 113.

The sensor(s) 414 may comprise, for example, a gyroscope, anaccelerometer, a compass, a GPS receiver, and/or the like. Accordingly,the sensor(s) 114 may be operable to determine movement, orientation,geographic position, and/or other physical characteristics of thetransceiver 120. The sensor(s) 114 may comprise, for example, ahygrometer, a psychrometer, and/or a radiometer. Accordingly, thesensor(s) 114 may be operable to determine atmospheric conditions and/orother physical obstructions between the transceiver 120 and potentiallink microwave backhaul link partners. The sensor(s) 414 may outputreadings/measurements as signal 415.

For receive operations, each front-end circuit 402 _(n) (1≦n≦N, whereN=8 in the example implementation depicted) is operable to receive amicrowave signal via feed line 304 _(n). The front-end circuit 402 _(n)processes the signal on feed line 304 _(n) by, for example, amplifyingit via a low noise amplifier LNA 420 _(n), filtering it via filter 426_(n), and/or downconverting it via mixer 424 _(n) to an intermediatefrequency or to baseband. The local oscillator signal 431 _(n) for thedownconverting may be generated by the circuit 404, as described below.The result of the processing performed by each front-end circuit 402_(n) is a signal 403 _(n).

The beamforming circuit 404 comprises local oscillator synthesizer 228operable to generate a reference local oscillator signal 429, andcomprises phase shift circuits 430 ₁-430 _(N) operable to generate Nphase shifted versions of signal 429, which are output as signals 431₁-431 _(N). The amount of phase shift introduced by each of the circuits430 ₁-430 _(N) may be determined by a corresponding one of a pluralityphase coefficients. The plurality of phase coefficients may becontrolled to achieve a desired radiation pattern of the antennaelements 306 ₁-306 ₄. In another example implementation, additionalfront-end circuits 402 and phase shifters 430 may be present to enableconcurrent reception of additional signals via the antenna elements 306₁-306 _(N).

The beamforming circuit 404 also comprises a circuit 432 which isoperable to perform weighting of the signals 403 ₁-403 ₈ by theirrespective amplitude coefficients determined for a desired radiationpattern. For reception, the circuit 432 is operable to combine theweighted signals prior to outputting them on signal 405. The circuit 404may also be operable to dynamically control interconnections betweensignals 403 ₁-403 ₈ and signals 405 and 441 to support differentconfigurations such as the full-duplex configuration as shown in FIG. 5A(e.g., transmit and receive on different frequencies or differentpolarizations of the same frequency), the configuration of FIG. 5B forconcurrent transmission of two different signals (e.g., transmit on twofrequencies or two polarizations of the same frequency), and theconfiguration of FIG. 5C for concurrent reception of two differentsignals (e.g., receive on two frequencies or two polarizations of thesame frequency).

In an example implementation, the phase and/or amplitude coefficientsmay be controlled/provided by the digital circuitry 408 via signal 416.The phase and amplitude coefficients may be adjusted dynamically. Thatis, the coefficients may be adjusted while maintaining one or moreactive backhaul links.

Dynamically adjusting the phase and/or amplitude coefficients duringreception of energy of microwave backhaul signals results incorresponding changes in the radiation pattern of the transceiver 120.Different patterns may capture different amounts of energy fromdifferent microwave backhaul signals. By adjusting the radiation patternintelligently, sufficient energy from multiple beams may be capturedduring a single time interval such that content carried in each of thebeams during that time interval can be demodulated and decoded with lessthan a threshold amount of errors. In other words, the “scanning” mayeffectively enable “illuminating” more of the reflector 116 than could asingle antenna element having the same dimensions as the overalldimensions of the array of antenna elements 306. As an example toillustrate, for a first radiation pattern (i.e., first set of phase andamplitude coefficients), energy received from a first microwave backhaulsignal may be above a threshold, but energy received from a secondmicrowave backhaul signal may be below the threshold. Conversely, for asecond radiation pattern, power received from the first microwavebackhaul signal may be below the threshold, but power received from thesecond microwave backhaul signal may be above the threshold.Accordingly, by dwelling on each of the two radiation patterns for asufficient percentage of a sufficiently short time interval, sufficientenergy may be captured for each of the microwave backhaul signals duringthat time interval such that the information on both microwave backhaulsignals during that time interval can be recovered.

In an example implementation, the phase and/or amplitude beamformingcoefficients may be controlled based on measured performance metrics ofone or more backhaul links 118. For example, the digital circuitry 408may continuously, or periodically, monitor a signal-to-noise ratio of alink 118 and may continuously, or periodically, adjust the coefficients(and thus the radiation pattern) in an attempt to maximize thesignal-to-noise ratio. This may improve performance in the presence ofdynamic misalignment (e.g., due to twist and sway cause by wind and/orwherein one or both of the microwave backhaul assemblies is mobile)and/or static misalignment (e.g., misalignment that resulted fromless-than-perfect installation of the transceiver 120.)

In an example implementation, the sensor(s) 414 may perform a compassfunction and may indicate an orientation of the transceiver 120. Thephase and/or amplitude beamforming coefficients (and thus the radiationpattern) may then be continuously or periodically adjusted based on theindicated orientation. This may improve performance of the backhaul link118 in the presence of dynamic misalignment (e.g., due to twist and swaycause by wind and/or wherein one or both of the microwave backhaulassemblies is mobile) and/or static misalignment (e.g., misalignmentthat resulted from less-than-perfect installation of the transceiver120.)

In an example implementation, the sensor(s) 414 may indicate movement ofthe transceiver 120. The phase and/or amplitude beamforming coefficients(and thus the radiation pattern) may then be continuously orperiodically adjusted based on the indicated movement. This may improveperformance of the backhaul link 118 in the presence of dynamicmisalignment (e.g., due to twist and sway cause by wind and/or whereinone or both of the microwave backhaul assemblies is mobile).

In an example implementation, the sensor(s) 414 may indicate atmosphericconditions through which microwave backhaul signals to and/or from thetransceiver 120 may travel. The phase and/or amplitude beamformingcoefficients (and thus the radiation pattern) may then be continuouslyor periodically adjusted based on the atmospheric conditions. This mayimprove performance of individual backhaul links 118, and/or of thenetwork as a whole, in the presence of rain, snow, fog, smog, or otheratmospheric conditions which negatively impact microwave communications.

In an example implementation, the phase and/or amplitude beamformingcoefficients may be controlled based on data retrieved from a localand/or networked database. Such data may include, for example, dataindicating geographical locations of other microwave backhaul assemblieswith which the transceiver 120 may desire to establish a microwavebackhaul link, and/or data indicating atmospheric conditions which mayimpact microwave communications.

The ADC 406 is operable to digitize signal 405 to generate signal 407.The bandwidth of the ADC 406 may be sufficient such that it canconcurrently digitize entire microwave backhaul bands comprising aplurality of channels or sub-bands (e.g., the ADC 406 may have abandwidth of 1 GHz or more).

The DAC 440 is operable to convert digital signal 439 (e.g., a digitalbaseband signal) to an analog signal 441.

For receive, the digital circuitry 408 is operable to process thedigital signals 407 for output to link 113. The processing may include,for example, interference (e.g., cross-polarization interference)cancellation. The processing may include, for example, channelization toselect, for output to the link 113, sub-bands or channels of the signal407. The processing may include, for example, band stacking, channelstacking, band translation, and/or channel translation to increaseutilization of the available bandwidth on the link 113.

For transmit, the digital circuitry 408 is operable to perform digitalbaseband processing for preparing data received via link 113 to betransmitted via the microwave backhaul link(s) 118. Such processing mayinclude, for example, processing of packets received via the link 113 torecover the payload data from such packets, and then packetization,modulation, etc. to generate a microwave backhaul digital basebandsignal 439 carrying the payload data.

The implementation of circuitry 302 shown in FIG. 4A may be realized onany combination of one or more semiconductor (e.g., Silicon, GaAs) diesand/or one or more printed circuit board. For example, each front-endcircuit 402 _(n) may comprise one or more first semiconductor dieslocated as close as possible to (e.g., a few centimeters from) itsrespective antenna element 306 _(N), the circuits 404 and 406 maycomprise one or more second semiconductor dies on the same PCB as thefirst die(s), the circuits 408 and 440 may reside on one or more thirdsemiconductor dies on the same PCB, and the sensor(s) 414 may bediscrete components connected to the PCB via wires or wirelessly.

FIG. 4B depicts a second example implementation of the circuitry 302. Inthis example implementation, the application of beamforming amplitudeand phase coefficients is performed in the digital domain in digitalcircuitry 408. That is, in addition to other functions performed bydigital circuitry 408 (such as those described above), the digitalcircuitry may also perform phase and amplitude weighting and combiningof the signals 413 ₁-413 ₈.

Each of the circuits 450 ₁-450 ₈ is operable to performdigital-to-analog conversion (when used for transmission) and/oranalog-to-digital conversion (when used for reception). In this regard,for reception, the signals 413 ₁-413 ₈ are the result of digitization ofthe signals 403 ₁-403 ₈ output by the front-ends 402 ₁-402 ₈. Fortransmission, the signals 413 ₁-413 ₈ are the result of digitalcircuitry 408 performing phase and amplitude weighting and combining ofone or more digital baseband signals (the weighting and combining may beas described in one of FIGS. 6A-6C).

The implementation of circuitry 302 shown in FIG. 4B may be realized onany combination of one or more semiconductor (e.g., Silicon, GaAs) diesand/or one or more printed circuit board. For example, each pair of 402_(n) and 450 _(n) may comprise an instance of a first semiconductor dieand may be located as close as possible to (e.g., a few centimetersfrom) its respect antenna element 306 _(n), the digital circuitry 408may comprise an instance of a second semiconductor die on the same PCBas the first dies, and the sensor(s) 414 may be discrete componentsconnected to the PCB via wires or wirelessly.

Referring now to FIG. 5A, there is shown a configuration of the circuit232 for concurrent reception of two microwave backhaul signals. Forexample, the signals 403 ₁-403 ₄ may be four versions (corresponding tofour antenna elements) of a first signal having a first polarization(e.g., horizontal) and feed lines 403 ₅-403 ₈ may be four versions of asecond signal having a second polarization (e.g., vertical). The firstand second signals may be on the same or different frequencies. Thesignals 403 ₁-403 ₄ are each weighted by a respective amplitudecoefficient and then the weighted signals are summed resulting in signal504, which corresponds to the signal received based on the radiationpattern achieved by the phase and amplitude coefficients applied to thesignals 403 ₁-403 ₄. Similarly, the signals 403 ₅-403 ₈ are eachweighted by a respective amplitude coefficient and then the weightedsignals are summed resulting in signal 506, which corresponds to thesignal received based on the radiation pattern achieved by the phase andamplitude coefficients applied to the signals 403 ₅-403 ₈. The circuit508 then combines (e.g., using time and/or frequency divisionmultiplexing) the signals 504 and 506 to generate the signal 405. Wherethe two signals are received from two different link partners, the phaseand amplitude coefficients for signals 403 ₁-403 ₄ may be set to achievea radiation pattern having a lobe (e.g., 804 of FIG. 8) pointing at thefirst link partner and the phase and amplitude coefficients for signals403 ₅-403 ₈ may be set to achieve a radiation pattern having a lobe(e.g., 808 of FIG. 8) pointing at the second link partner.

Now referring now to FIG. 5B, there is shown a configuration of thecircuit 232 for concurrent transmission of two microwave backhaulsignals. For example, the signals 403 ₁-403 ₄ may be four versions of afirst signal to be transmitted with a first polarization (e.g.,horizontal) and signals 403 ₅-403 ₈ may be four versions of a secondsignal to be transmitted with a second polarization (e.g., vertical).The first and second signals may be on the same or differentfrequencies. The signal 411 carries two baseband signals which aresplit, by circuit 508, into first signal 510 and second signal 512. Fouramplitude coefficients are applied to signal 510 to generate signals 403₁-403 ₄. The signals 403 ₁-403 ₄ are output, respectively, to front-ends402 ₁-402 ₄ where respective phase coefficients are applied beforeoutputting the signals to the antenna elements 306 ₁-306 ₄ via feedlines 304 ₁-304 ₄. Similarly, four amplitude coefficients are applied tosignal 512 to generate signals 403 ₅-403 ₈. The signals 403 ₅-403 ₈ areoutput, respectively, to front-ends 402 ₅-402 ₈ where respective phasecoefficients are applied during upconversion before the signals areoutput to the antenna elements 306 ₁-306 ₄ via feed lines 304 ₅-304 ₈.Where the two signals are destined for two different link partners, thephase and amplitude coefficients for signals 403 ₁-403 ₄ may be set toachieve a radiation pattern having a lobe (e.g., 804 of FIG. 8) pointingat the first link partner and the phase and amplitude coefficients forsignals 403 ₅-403 ₈ may be set to achieve a radiation pattern having alobe (e.g., 808 of FIG. 8) pointing at the second link partner.

Now referring now to FIG. 5C, there is shown a configuration of thecircuit 232 for concurrent transmission of a first microwave backhaulsignal and reception of a second microwave backhaul signal. The firstsignal is received on a first polarization via feed lines 304 ₁-304 ₄,application of phase coefficients for the desired radiation pattern areapplied in front-ends 402 ₁-402 ₄, resulting in signals 403 ₁-403 ₄.Amplitude coefficients for the desired radiation pattern are applied tosignals 403 ₁-403 ₄ in circuit 232, and finally the phase and amplitudeweighted signals are combined to generate signal 405. The second signalarrives at circuit 232 as signal 441. The amplitude coefficients areapplied resulting in signals 403 ₅-403 ₈ which are output to front-ends402 ₅-402 ₈ where phase coefficients are applied during upconversionbefore the signals are output to feed lines 304 ₅-304 ₈ for transmissionon the second polarization. Where the first signals is received from afirst link partner but the second signals is destined for a second linkpartners, the phase and amplitude coefficients for signals 403 ₁-403 ₄may be set to achieve a radiation pattern having a lobe (e.g., 804 ofFIG. 8) pointing at the first link partner and the phase and amplitudecoefficients for signals 403 ₅-403 ₈ may be set to achieve a radiationpattern having a lobe (e.g., 808 of FIG. 8) pointing at the second linkpartner.

Now referring to FIGS. 6A-6C, shown are three configurations ofbeamforming circuitry of the digital circuitry 408 of FIG. 4B. Theconfigurations in FIGS. 6A-6C are similar to the respectiveconfigurations of circuitry 232 shown in FIGS. 5A-5C. A difference inFIGS. 6A-6C is that the phase and amplitude coefficients are bothapplied in circuit 408, as opposed to the phase coefficient beingapplied in the front-ends 402. Another difference is that the phase andamplitude coefficients are applied in the digital domain as opposed toin the analog domain in FIGS. 5A-5C.

As discussed above, the radiation pattern of the antenna array 202 maybe dynamically adjusted. FIG. 7A shows adjustment of the azimuth angle(labeled 0) of the lobe 206. Shown are three positions of the lobe 206corresponding to three sets of phase and/or amplitude coefficients. Thefirst set of coefficients corresponding to the lobe 206 having θ=0°, thesecond set of coefficients corresponding to the lobe 206 ^(−θ) which isshifted in the −θ direction by an amount 706, and the third set ofcoefficients corresponding to the lobe 200 which is shifted in the +θdirection by an amount 708. FIG. 7B shows adjustment of the elevationangle (labeled φ) of the lobe 206. Shown are three positions of the lobe206 corresponding to three sets of phase and/or amplitude coefficients.The first set of coefficients corresponding to the lobe 206 having φ=0°,the second set of coefficients corresponding to the lobe 206 ^(+φ) whichis shifted in the +φ direction by an amount 710, and the third set ofcoefficients corresponding to the lobe 206 ^(−φ) which is shifted in the−φ direction by an amount 608.

In accordance with an example implementation of this disclosure, a firstmicrowave backhaul transceiver (e.g., 120 a) may comprise a reflector(e.g., 116 a) and a signal processing subassembly (e.g., 114 a). Thesignal processing subassembly may comprise a plurality of antennaelements (e.g., 306) positioned at a focal plane of the reflector. Thesignal processing subassembly may process a plurality of microwavesignals (e.g., on two or more of feed lines 304 ₁-304 ₈) correspondingto the plurality of antenna elements using a corresponding plurality ofphase coefficients and a corresponding plurality of amplitudecoefficients. The signal processing subassembly may adjust a radiationpattern of the plurality of antenna elements during operation of thesignal processing subassembly through adjustment of the phasecoefficients and/or the amplitude coefficients. The circuitry maycomprise a local oscillator generator (e.g., 228) and a plurality ofphase shifters (e.g., 430 ₁-430 ₈). Each of the plurality of phaseshifters may be configured by a respective one of the plurality of phasecoefficients. An output of the local oscillator generator is coupled toan input of each of the plurality of phase shifters. An output of eachof the phase shifters may be coupled to a respective one of a pluralityof mixers (e.g., 424) be operable to downconvert a respective one of themicrowave signals, resulting in a plurality of phase-shifteddownconverted signals (e.g., signals 403 ₁-403 ₈). The circuitry maycomprise a combiner (e.g., 432 or circuitry of digital circuitry 408)which is operable to generate a weighted sum of the plurality ofphase-shifted downconverted signals, wherein weights used for theweighted sum are the amplitude coefficients. The circuitry may comprisea plurality of analog front-ends (e.g., 402 ₁-402 ₈) operable todownconvert the plurality of microwave signals (e.g., on lines 304 ₁-304₈) to generate a plurality of downconverted signals (e.g., 403 ₁-403 ₈).The circuitry may comprise a plurality of analog-to-digital converters(e.g., 450 ₁-450 ₈), each of which is operable to digitize a respectiveone of the plurality of downconverted signals. The circuitry may beoperable to apply the plurality of phase coefficients and the pluralityof amplitude coefficients to the plurality of downconverted signals.

The present method and/or system may be realized in hardware, software,or a combination of hardware and software. The present methods and/orsystems may be realized in a centralized fashion in at least onecomputing system, or in a distributed fashion where different elementsare spread across several interconnected computing systems. Any kind ofcomputing system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may be a general-purpose computing system with a program orother code that, when being loaded and executed, controls the computingsystem such that it carries out the methods described herein. Anothertypical implementation may comprise an application specific integratedcircuit or chip. Some implementations may comprise a non-transitorymachine-readable (e.g., computer readable) medium (e.g., FLASH drive,optical disk, magnetic storage disk, or the like) having stored thereonone or more lines of code executable by a machine, thereby causing themachine to perform processes as described herein.

While the present method and/or system has been described with referenceto certain implementations, it will be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted without departing from the scope of the present methodand/or system. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the presentdisclosure without departing from its scope. Therefore, it is intendedthat the present method and/or system not be limited to the particularimplementations disclosed, but that the present method and/or systemwill include all implementations falling within the scope of theappended claims.

What is claimed is:
 1. A system comprising: a first microwave backhaultransceiver comprising: a reflector, and a signal processing subassemblyoperable to: process a plurality of microwave signals corresponding tosaid plurality of antenna elements using a corresponding plurality ofphase coefficients and a corresponding plurality of amplitudecoefficients; and adjust a radiation pattern of said plurality ofantenna elements during operation of said signal processing subassemblythrough adjustment of said phase coefficients and/or said amplitudecoefficients, wherein said signal processing subassembly comprises: aplurality of antenna elements positioned at a focal plane of saidreflector, and circuitry that comprises: a local oscillator generator,and a plurality of phase shifters, each of said plurality of phaseshifters being operably coupled to an output of the local oscillatorgenerator, each of said plurality of phase shifters being configured bya respective one of said plurality of phase coefficients.
 2. The systemof claim 1, wherein: an output of each of said phase shifters is coupledto a respective one of a plurality of mixers operable to downconvert arespective one of said plurality of microwave signals; and outputs ofsaid plurality of mixers are a plurality of phase-shifted downconvertedsignals.
 3. The system of claim 2, wherein said circuitry comprises acombiner which is operable to generate a weighted sum of said pluralityof phase-shifted downconverted signals, wherein weights used for saidweighted sum are said amplitude coefficients.
 4. The system of claim 1,wherein: said circuitry comprises a plurality of analog front-endsoperable to downconvert said plurality of microwave signals to generatea plurality of downconverted signals; said circuitry comprises aplurality of analog-to-digital converters, each of which is operable todigitize a respective one of said plurality of downconverted signals;said circuitry is operable to apply said plurality of phase coefficientsand said plurality of amplitude coefficients to said plurality ofdownconverted signals.
 5. The system of claim 1, wherein: said circuitrycomprises one or more sensors operable to detect orientation of saidfirst microwave backhaul transceiver; and said circuitry is operable toperform said adjustment of said phase coefficients and/or said amplitudecoefficients based on said orientation.
 6. The system of claim 1,wherein: said circuitry comprises one or more sensors operable to detectgeographic location of said first microwave backhaul transceiver; andsaid circuitry is operable to perform said adjustment of said phasecoefficients and/or said amplitude coefficients based on said geographiclocation.
 7. The system of claim 1, wherein: said circuitry is operableto determine a performance metric for a microwave backhaul link betweensaid first microwave backhaul transceiver and a second microwavebackhaul transceiver; and said circuitry is operable to perform saidadjustment of said phase coefficients and/or said amplitude coefficientsbased on said performance metric.
 8. The system of claim 1, wherein:said circuitry is operable to determine atmospheric conditions betweensaid first microwave backhaul transceiver and one or more secondmicrowave backhaul assemblies; and said circuitry is operable to performsaid adjustment of said phase coefficients and/or said amplitudecoefficients based on said atmospheric conditions.
 9. The system ofclaim 1, wherein said radiation pattern has multiple lobes pointed inmultiple directions for concurrently supporting multiple microwavebackhaul links in said multiple directions.
 10. A method comprising: ina first microwave backhaul transceiver comprising a reflector and asignal processing subassembly, wherein said signal processingsubassembly comprises a plurality of antenna elements positioned at afocal plane of said reflector: processing a plurality of microwavesignals corresponding to said plurality of antenna elements using acorresponding plurality of phase coefficients and a correspondingplurality of amplitude coefficients; configuring a plurality of phaseshifters of microwave backhaul transceiver based said plurality of phasecoefficients; generating a local oscillator signal; processing saidlocal oscillator signal via said plurality of phase shifters to generatea plurality of phase-shifted local oscillator signals; and adjusting aradiation pattern of said plurality of antenna elements during operationof said signal processing subassembly by adjusting said phasecoefficients and/or said amplitude coefficients.
 11. The method of claim10, comprising: downconverting said plurality of microwave signals via aplurality of mixers having their local oscillator inputs coupled to saidplurality of phase-shifted local oscillator signals, said downconvertingresulting in a plurality of phase-shifted downconverted signals.
 12. Themethod of claim 11, comprising: weighting said plurality ofphase-shifted downconverted signals with said plurality of amplitudecoefficients, said weighting resulting in amplitude scaled and phaseshifted downconverted signals; and combining said amplitude-scaled andphase-shifted downconverted signals.
 13. The method of claim 10,comprising: downconverting said plurality of microwave signals in acorresponding plurality of analog front-ends, said downconvertingresulting in a plurality of downconverted signals; digitizing saidplurality of downconverted signals; phase shifting said plurality ofdownconverted signals based on said plurality of phase coefficients; andscaling an amplitude of said plurality of downconverted signals based onsaid plurality of amplitude coefficients.
 14. The method of claim 10,comprising: detecting orientation of said first microwave backhaultransceiver via one or more sensors installed with said first microwavebackhaul transceiver; and adjusting said phase coefficients and/or saidamplitude coefficients based on said orientation.
 15. The method ofclaim 10, comprising: detecting geographic location of said firstmicrowave backhaul transceiver via one or more sensors installed withsaid first microwave backhaul transceiver; and adjusting said phasecoefficients and/or said amplitude coefficients based on said detectedgeographic location.
 16. The method of claim 10, comprising: determininga performance metric for a microwave backhaul link between said firstmicrowave backhaul transceiver and a second microwave backhaultransceiver; and adjusting said phase coefficients and/or said amplitudecoefficients based on said performance metric.
 17. The method of claim10, comprising: determining atmospheric conditions between said firstmicrowave backhaul transceiver and one or more second microwave backhaultransceivers; and adjusting of said phase coefficients and/or saidamplitude coefficients based on said atmospheric conditions.
 18. Themethod of claim 10, wherein said radiation pattern has multiple lobespointed in multiple directions for concurrently supporting multiplemicrowave backhaul links in said multiple directions.